Polishing apparatus



2 Sheets-Sheet l P. M. DREILING POLISHING APPARATUS I 7/ UM I INVENTOR. PETER M. DREILING drus gt Std/IQ Affbnuzvs June 18, 1968 Filed Jan. 12, 1965 June 18, 1968 P. M. DREILING POLISHING APPARATUS .2 Sheets-Sheet 2 Filed Jan. 12, 1965 INVENTOR. PETER M. DREILING drus t sung A'fdmuevs United States Patent 3,388,505 POLISHING APPARATUS Peter M. Dreiling, Sheboygan, Wis., assignor to iii-Lite Polishing Machine Company, Inc., Shehoygan, Wis., a corporation of Wisconsin Filed Jan. 12, 1965, Ser. No. 424,909 Claims. (Cl. 51-1345) ABSTRACT OF THE DISCLOSURE A polishing apparatus including a fixed, non-rotating core shaped to the configuration of the part to be polished. A spring assembly, which includes at least two helical coil springs wound in opposite directions, is disposed around the fixed core. One end of the spring assembly is connected to a drive mechanism and the other end of the spring assembly carries an abrasive member which is adapted to polish the surface of the workpiece.

The core is secured to a fixed support and the spring assembly provides a positive drive to rotate the abrasive member while the non-rotating core maintains alignment of the abrasive member with the workpiece.

In addition, the central non-rotating core is provided with a longitudinal passage and a lubricating medium is introduced into the passage and is discharged through a series of radial ports to lubricate the spring assembly as well as the workpiece.

This invention relates to a polishing apparatus and more particularly to an apparatus for polishing or grinding the interior surface of angular members such as elbows and TS.

Pipe or conduit used in the dairy, food processing and brewery industries is generally formed of stainless steel and has polished, or otherwise finished, interior surfaces to minimize contamination. While the interior surfaces of straight sections of pipe can be polished by automatic equipment, the polishing of the interior surfaces of angular pipe sections, such as elbows and Ts, has not, in the past, been satisfactorily accomplished by machine operations so that normally the interior surfaces of angular members are polished by hand. With a hand operation, a small grinding or polishing wheel on a short, straight shaft is introduced into each end of the elbow and approximately one-half of the interior surface is polished from each end. This manual polishing of angular members provides a relatively uneven polished surface and results in a blen line at the center of the section where the polishing operation from each end overlaps. The most serious problem resulting from the manual polishing of the interior surface of elbows and Ts is that the polishing is a difficult operation and takes a substantial period of time which greatly increases the overall labor cost of the element.

The present invention is directed to a polishing head for automatically polishing or grinding the interior surfaces of angular members such as elbows and Ts. According to the invention the polishing head includes a fixed non-rotating core which is shaped to the configuration of the part to be polished. A spring assembly, which includes at least two helical coil springs wound in opposite directions, is disposed around the fixed core. One end of the spring assembly is connected to a drive mechanism and the other end of the spring assembly carries an abrasive member which is adapted to polish the interior surface of the workpiece.

The polishing head is provided with an orbital movement and the workpiece is moved through an arc onto the polishing head to thereby polish the entire length of the workpiece.

The coil springs wound in opposite directions provide "ice a positive drive through the curved or angular portion to rotate the abrasive member, while the non-rotating core maintains alignment of the abrasive member with the workpiece.

The central non-rotating core is provided with a longitudinal passage and a lubricating medium such as oil is introduced into the passage and is discharged through a series of radially extending outlets which are located within the spring assembly. The oil continually passes through the springs to lubricate the springs and also lubricates the workpiece in the polishing area.

The polishing machine of the invention completely and uniformly polishes the entire interior surface of hollow members, such as elbows, from one end. The elbow or other hollow member does not have to be reversed and there is no blend-line or overlapping of polishing at the central portion of the workpiece and is normally provided by conventional polishing operations.

Probably the most important advantage of the present invention is the substantial savings in time which results by use of the machine. The time required for polishing the interior surface of an elbow is reduced to about onequarter of the time required for a manual polishing operation.

The drive mechanism of the invention, while particularly adaptable to a polishing machine, can be used in any situation where it is desired to provide an angular transfer of motion from a drive member to a working member.

Other objects anl advantages will appear in the course of the following description.

The drawings illustrate the best mode presently contemplated of carrying out the invention.

FIGURE 1 is a side elevation with parts broken away in section showing the polishing head of the invention.

FIG. 2 is an enlarged fragmentary vertical section showing the spring drive assembly.

FIG. 3 is an enlarged side elevation of the spring drive and the core with parts broken away; and

FIG. 4 is a transverse section shown along line 4-4 of FIG. 2.

The drawings illustrate a polishing head 1 which is adapted to polish or otherwise finish the interior surface of an angular member, such as elbow 2.

The polishing head includes a fixed, non-rotating core 3 which is provided with a curved or angular lower end portion 4 having a configuration corresponding to that of the elbow 2 to be polished. The upper end of the core 3 is secured within a split ring clamp 5 which is mounted on a frame or other outside object and prevents rotation of the core 3.

A rotatable sleeve 6 is spaced outwardly from the core 3 and is journaled for rotation within a pair of bearing assemblies 7 and 8 which are mounted in bearing housing 9. The housing 9 is secured to the stationary frame of the machine, and the upper end of the housing is enclosed by a cap 10, and a lock nut 11 is located upwardly of the cap. The sleeve housing 9 is retained in position on the sleeve 5 by lock rings 12.

To rotate the sleeve 6, a pulley 13 is secured to the upper portion of the sleeve and is connected through a belt drive 14 to the drive shaft of a motor. In addition to the bearing assemblies 7 and 8, a bearing assembly 15 is located within the lower end of the sleeve and serves to maintain alignment of the core within the sleeve and journal the sleeve about the core 3.

The lower end of the rotatable sleeve 6 is connected to the upper end of a coil spring assembly 16 which is composed of a series of superimposed, helically wound, coil springs. As shown in the drawings, three coil springs 17, 18 and 19 are employed, with each coil spring having the opposite helix angle. For example, the inner coil spring 17 has the opposite helix angle from the intermediate coil spring 8, and the outer coil spring 19 has the same helix angle as the inner coil spring 17. Tue coil spring assembly 16 is disposed around the bent or curved portion 4 of core 3 and in some areas, the inner spring 17 will actually engage the core.

Each spring 17, 18 and 19 is formed of a series of convolutions and the convolutions are positioned in a sideby-side relation so that there are no gaps between convolutions in the wound spring. Each convolution or winding is preferably composed of two or more strands or wires, as shown in FIG. 3.

The upper end of the coil spring assembly 16 is soldered or otherwise connected within a recess in a cupshaped connecting member 2%, which has a central opening to receive the core 3. A series of balls 21 are located within sockets 22 formed in the outer surface of connector 2i) and each ball is positioned within a groove 23 in the lower end of the sleeve 6. The balls 21 are forced into the sockets 22 by a wedge cap 24 which is disposed around the sleeve 6 and is provided with an internal tapered or wedging surface which engages the outer periphery of the ball and forces the ball inwardly into the socket 22. The wedge cap 24 is urged downwardly toward the spring assembly by a coil spring 25 which is interposed between the wedge cap 24 and a ring 25.

The use of the ball connection serves to transfer rotary motion from the sleeve 6 to the connector 28 to thereby rotate the springs of the spring assembly 16. This connection can be readily released by merely compressing the spring 25 and withdrawing the connector 20 from the end of the sleeve 6, and thereby enables the entire coil spring assembly 16 to be readily changed and replaced when desired.

The lower end of the coil spring assembly 16 is connected to a working member such as a grinding wheel unit 27. The wheel unit 27 is formed of two halves or sections 28 and 29 and the end of the coil spring assembly is soldered or secured within a recess in the inner wheel section 28.

The hub of the outer wheel section 29 is threaded within the hub of the inner section 28, and the outer section 29 is journaled for rotation about a pin 30 which is threaded within a recess in the end of core 3. With this construction the wheel 27 will be driven by the spring assembly 16 and will rotate about the pin 30.

A resilient disc 31, formed by polyurethane resin or the like, is positioned between the wheel sections 28 and 29, and an abrasive ring 32 is located around the outer periphery of disc 31. As section 29 is threaded down, the disc 31 will be squeezed or deformed with the result that the disc will expand radially against the abrasive ring 32 to more firmly secure the ring. In addition, the outer surface or periphery of the disc 31 will tend to become curved or rounded as the disc is deformed by pressure of section 29, with the result that the rounded edges will prevent the abrasive ring from digging in or scoring the elbow, particularly in the curved section of the elbow.

The coil spring assembly 16, which includes at least two oppositely wound coil springs, serves to transfer the rotary motion from the sleeve 6 to the abrasive wheel 27. If a single spring is used, rotation of the spring in one direction will tighten the spring on itself, while rotation in the other direction will open the spring so that it cannot drive. With two springs wound in opposite directions, the inner spring will tend to open up during rotation in one direction, while the outer spring will tend to compress so that they fight against each other and a positive drive is provided. However, if the two springs are rotated in the opposite direction, the inner spring will tend to compress, while the outer spring will open up so that no positive drive is provided. Thus, at least two oppositely wound springs are needed to provide drive in one direction and at least three oppositely wound springs are required in order to permit drive in both directions.-

Three oppositely wound springs also provide more stability when driving in one direction.

During polishing, a lubricating medium, such as oil, is introduced into the hollow interior 33 of the core 3. As shown in FIG. 1, an oil line 34 which is connected to a supply of oil, is threaded onto the upper end of the core 3 and communicates with the central opening 33, so that oil will flow downwardly within the passage 33. A series of radial outlet ports 35 are provided in the straight vertical portion of core 3, and oil passes outwardly through the ports 35 and fills the annular passage 36 etween the core 3 and the rotating sleeve 6. The oil within the passage 36 flows downwardly to lubricate the lower bearing assembly 15. An oil seal 37 is located at the upper end of passage 36 to prevent the oil from flowing upwardly out of the passage 36.

In addition to the outlet ports 35, the lower bent end 4 of the core is also provided with a plurality of radial outlet ports 38 and the oil flows outwardly through the ports 38 through the springs 17, 18 and 19 to lubricate the springs. In addition, the excess oil passing through the spring assembly 15 will contact the inner surface of the elbow 2 to provide a lubricating film on the surface of the elbow which aids in the polishing operation.

In operation of the polishing head, the sleeve 6 is rotated through the belt drive 14- and rotation of the sle ve is transmitted to the coil spring assembly 16 to rotate the polishing wheel unit 27. Simultaneously with the rotation of the polishing wheel, the entire polishing head 1 is moved in a generally oval or orbital path of motion so that the abrasive member 32 will contact the entire inner surface of the elbow 2. The elbow 2 is also moved through an arcuate path up and over the spring assembly 16 so that the abrasive member 32 will Contact the entire length of the elbow. For most polishing operations, the elbow is moved upwardly in a forward stroke to a position shown in the phantom line in FIG. 1, and then is moved in the opposite direction in a return stroke, with polishing being done on both the forward and return strokes.

The polishing head of the invention provides a uniform polishing operation on the interior surface of the elbow or other angular member. The entire length of the workpiece is polished from one end and the workpiece does not have to be reversed to complete the polishing operation. Moreover, there is no blend line or overlapping of polishing at the central position of the elbow, as normalley occurs with conventional hand-polishing operations.

The non-rotating rigid core and the spring assembly 16 cooperate to provide a curved or angular drive mechanism. The core maintains the desired shape or configuration of the spring assembly 16 and enables pressure to be applied through the wheel unit 27 to the inner surface of the elbow 2 thereby insuring uniform polishing of the interior surface. The spring assembly itself provides a flexible drive for the angular or curved configuration.

The use of the polishing head of the invention provides a substantial saving in the time required for polishing the interior surface of curved or angular members, and this time saving in labor materially reduces the overall cost of the article.

While the above description has been directed to the use of the polishing head in polishing or grinding curved or angular members it is contemplated that the polishing head can also be employed to polish the inner surface of straight members. In this situation, the core 3, while being substantially rigid, has a considerable length and the outer end of the core carrying the working member will tend to bend or deflect slightly when pressure is applied through the working member against the workpiece. This bending or deflecting of the core provides a resilient action which enables the working member to follow irregularities or deformities in the surface of the workpiece, thereby insuring a uniform polishing action on the workpiece.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A polishing apparatus, comprising a rigid, non-rotatable core, a rotatable member disposed for rotation around the core, means for rotating said rotatable member, means for securing said core to a support and preventing rotation of the core, a spring assembly disposed around the core and including a series of oppositely wound coil springs, said core extending throughout the length of the spring assembly, means for removably connecting one end of the spring assembly to the rotating member, and a Working member connected to the opposite end of the spring assembly and mounted for rotation on the core.

2. The structure of claim 1 in which the core is provided with a hollow interior and is provided with at least one outlet port communicating with the hollow interior, and means for introducing a lubricating medium into the hollow interior of the core with said medium passing outwardly through the port to lubricate the springs and the workpiece to be polished.

3. In an apparatus of the class described, a rigid fixed core having a first generally straight portion and a second portion disposed at an angle to said first portion, means secured to said core for preventing rotation of the core, a spring assembly disposed around said second portion of said core and including at least two oppositely wound flexible coil springs, means for rotating one end of the spring assembly, and a working member connected to the opposite end of said spring assembly and adapted to perform a working operation on a workpiece, said spring assembly serving to transmit rotation to the working memher.

4. A polishing head, comprising a fixed core having an upper generally vertical portion and a lower curved portion, a rotatable sleeve disposed for rotation around the vertical portion of the core with the upper end of the core extending upwardly beyond said sleeve, means secured to the upper end of the core for preventing rotation of the core, a spring assembly disposed around the curved lower portion of said core and including a series of oppositely wound coil springs, means for connecting the upper end of the spring assembly to the sleeve, and an abrasive member connected to the lower end of said spring assembly.

5. A polishing head, compris ng a non-rotating core having a first generally straight portion and a second contoured portion, a sleeve disposed concentrically around the straight portions of the core and spaced outwardly therefrom, means for journaling the sleeve for rotation, means for rotating said sleeve, means secured to the core for preventing rotation of the core, a spring assembly disposed around the second portion of said core and including a plurality of oppositely wound coil springs, means for removably connecting one end of the spring assembly to the sleeve, an abrasive member connected to the opposite end of said spring assembly, and means for journaling the abrasive member on the second portion of the core.

6. A polishing head for polishing the interior surface of angular members, comprising a rigid core having a first generally straight portion and a second portion disposed at an angle to said first portion, said core having a longitudinally extending passage, a rotatable sleeve disposed for rotation around the straight portion of the core, means for rotating said sleeve, bearing means for journaling the sleeve for rotation about the core, a spring assembly disposed around said second portion of the core and including a series of oppositely wound coil springs, means for removably connecting one end of the spring assembly to the sleeve, a polishing member c nnected to the opposite end of said spring assembly, said second portion of the core being provided with a plurality of outlet ports extending between the longitudinal passage and the exterior of said core, and means for introducing a lubricating medium into the longitudinal pessage with said medium flowing outwardly through the ports to lubricate the springs and the workpiece to be polished.

7. The structure of claim 6, in which the sleeve is spaced outwardly of the straight portion of the core to provide an annular chamber therebetween and said straight portion of the core is provided with at least one hole communicating between the longitudinal passage and said annular chamber, said lubricating medium passing outwardly through said hole into said chamber.

8. A drive mechanism, comprising a substantially rigid non-rotatable core, means for preventing rotation of said core, a spring assembly disposed around said core and including at least two oppositely wound coil springs, sa d core extending throughout the length of the spring assernbly, drive means connected to one end of the spring assembly for rotating said spring assembly, and a working member journalled for rotation on the core and connected to the opposite end of said spring assembly.

9. A drive mechanism, comprising a rigid nonmotatable core including a generally curved section, means for preventing rotation of said core, a spring assembly disposed around said curved section and including at least two oppositely wound coil springs, drive means connected to one end of the spring assembly for rotating said spring assembly, a working member connected to the opposite end of said spring assembly, said core being provided with a longitudinal passage extending within said curved section, and said curved section being provided with at least one outlet port communicating between the longitudinal passage and the exterior of the core, and means for introducing a lubricating medium into the longitudinal passage of the core with said medium passing outwardly through the port to lubricate the springs.

10. A drive mechanism, comprising a substantially rig d non-rotatable elongated core, means for preventing rotation of said core, a spring assembly disposed around said core and including at least two oppositely wound coil springs, drive means connected to one end of the spring assembly for rotating said spring assembly, a working member connected to the opposite end of said spring assembly, said core being provided with a longitudinal passage and said core having at least one outlet port communicating between the longitudinal passage and the exterior of the core, and means for introducing a lubricating medium into the longitudinal passage of the core with said medium passing outwardly through the port to lubricate the springs.

References Cited UNITED STATES PATENTS 1,734,427 11/1929 Gray.

1,737,707 12/1929 Dickson 51-90 2,090,174 8/ 1937 Albright 642 2,704,005 3/1955 Clayson 642 X 3,044,220 7/ 1962 Emerson 51,90 X 3,260,069 7/ 1966 Neilson 642 2,006,630 7/1935 Dutro 51-24l.l 2,084,175 6/ 1937 Zimmerman 51-24l.1

LESTER M. SWINGLE, Primary Examiner.

ROBERT C. RIORDON, Examiner.

D. G. KELLY, Assistant Examiner. 

